1. Field of the Invention
The present invention relates, in general, to an apparatus for measuring dimensions of a spacer grid for nuclear fuel assemblies and, more particularly, to an apparatus for measuring dimensions of a spacer grid for nuclear fuel assemblies, capable of measuring all the sides of the spacer grid that support the nuclear fuel assemblies to accurately detect abnormalities in the spacer grid, preventing the spacer grids from interfering with each other, and preventing malfunctions from occurring in the real situation of a nuclear reactor in advance to provide reliability.
2. Description of the Related Art
Atomic power generation based on a light water reactor is designed to generate energy via the fission of nuclear fuel and use the energy to heat primary cooling water, transmit the energy of the heated primary cooling water to secondary cooling water in a steam generator to generate steam, convert the generated steam into rotational energy with a steam turbine, and produce electricity with a generator.
In general, apparatuses that measure spacer grids for the light water reactor measure all the sides of a spacer grid for a plurality of nuclear fuel assemblies stored at a fuel storage place.
All the sides of the spacer grid are measured using such a spacer grid measuring apparatus, thereby detecting abnormalities in the sides of the spacer grid.
Examples of the related art include Korean Patent No. 10-0784008, entitled “NUCLEAR FUEL ASSEMBLY LOW PRESSURE DROP TOP NOZZLE” and Korean Patent Application Publication No. 10-2001-0029780, entitled “FUEL ASSEMBLY MECHANICAL FLOW RESTRICTION APPARATUS FOR DETECTING FAILURE IN SITU OF NUCLEAR FUEL RODS IN A FUEL ASSEMBLY DURING REACTOR SHUTDOWN.”
As shown in FIG. 1, an apparatus for measuring a spacer grid of the related art includes a fixing unit 10 fixed to a measuring table 30 placed on a floor and kept safe from vibrations caused by external force.
A pair of measuring units 20 is mounted on the fixing unit 10. The pair of measuring units 20 is capable of grasping both sides of a rectangular spacer grid 40 disposed therein and moving in forward and backward directions, thereby measuring the both sides of the spacer grid 40.
However, the measuring units are too short to measure the whole length of the sides of the spacer grid, so that there can be unmeasured portions.
Thus, abnormalities in the unmeasured portions of the spacer grid cause abnormal effects in the supported nuclear fuel assemblies when operated.